The present invention relates to overlay structures. More specifically, the present invention is directed to a keypad overlay membrane configured to aid the user in striking the desired input key on an electronic device.
Modern handheld electronic devices, such as cellular telephones, PDAs and other mobile computing devices, typically have a keypad interface where a user depresses individual keys to input certain information and commands. One particular limitation of most electronic device keypads is the fact that individual keys are small, with little space therebetween. As a result, a user will often strike one or more keys unintentionally when attempting to engage a particular key or sequence of keys, leading to lost time and productivity in having to make corrections. This problem is exacerbated in certain industrial or outdoor environments where a user is required to wear gloves or otherwise has reduced visibility. In the case of gloves, the user has an even more difficult time limiting keystrikes to individual keys, and reduced visibility makes it even more difficult to read the small indicia printed onto most conventional keys.
Some solutions that have been proposed for dealing with inaccurate keystrikes including adding key extensions that mount onto individual keys of a conventional keyboard. As one example, a set of projecting structural members can be attached to the keys so that the user does not have to reach as far to strike a desired key. These solutions, however, focus on large conventional keyboards, and are impractical for attachment to a small keypad of a handheld electronic device.